Cole's operation was not major but could sideline him for a portion of the spring practices. The 30-year-old defensive end has reportedly been dealing with the issue for over a year, which could explain why he suffered through such a miserable season in 2012. He collected just three sacks and 24 tackles, both easily career lows. He also endured a career-long stretch of eight games without a sack.

That could be the result of his injury. It could be the fact that he is now 30 years old, the age when a lot of NFL players start to lose a step (see: Asomugha, Nnamdi). Or it could be the result of the Eagles' wide-nine defense led by defensive line coach Jim Washburn, which was ended when the Eagles fired Washburn late in the season.

The Eagles led the NFL with 50 sacks in 2011 but dropped to 30 in 2012. If Cole can return to his old form, collecting 10 to 11 sacks per season, the Eagles defensive line will return to being one of the more dominant in the game.

Cole has earned two Pro Bowl selections since he was drafted in the fifth round in 2005. He signed a contract extension last year that will keep him in Philadelphia through the 2017 season when he will be 35 years old.

He currently ranks third in franchise history with 71 career sacks, behind Reggie White and Clyde Simmons, including four seasons of double-digit sacks.